Add a story path when no user input found

hi I wanted to know if there is a way to set stories such as

- story: find effective document happy path
    - intent: greet
    - action: action_greet
    - intent: effective_document
    - slot_was_set:
      - effective_doc_number: "123543A"
    - action: action_find_effective_document
    - action: action_restart

this is when user entity value was already given there, I want to add a path where if no user input given, it should prompt for it, if given then follow the above path, how do I check for that where entity/slot is of text type?

What do you mean by

I want to add a path where if no user input given

Do you mean where the user says nothing at all, or where their input does not contain the info you need?

Input doesn’t contain the info i need

In that case, you probably want to use a Form with a validation method for the slot which handles exactly the situation where you want to collect some info and re-ask when it wasn’t provided.